grpcio==1.8.x release logs messages that shouldn't be there #13855
Description
This happens consistently (i.e. every time) on the first call to grpc.secure_channel and logs three messages about the GRPC_LINUX_EPOLL environment variable.
$ python -m virtualenv --python=python3.6 venv
$ venv/bin/python -m pip install grpcio google-auth requests
$ venv/bin/python -m pip show grpcio
Name: grpcio
Version: 1.8.2
...
$ venv/bin/python
>>> target = 'pubsub.googleapis.com:443'
>>> scopes = ('https://www.googleapis.com/auth/pubsub',),
>>>
>>> import google.auth
>>> credentials, _ = google.auth.default(scopes=scopes)
>>>
>>> import google.auth.transport.requests
>>> request = google.auth.transport.requests.Request()
>>>
>>> import google.auth.transport.grpc
>>> metadata_plugin = google.auth.transport.grpc.AuthMetadataPlugin(
... credentials, request)
>>>
>>> import grpc
>>> google_auth_credentials = grpc.metadata_call_credentials(metadata_plugin)
>>> ssl_credentials = grpc.ssl_channel_credentials()
>>> composite_credentials = grpc.composite_channel_credentials(
... ssl_credentials, google_auth_credentials)
>>>
>>> # Now the logging message happens
...
>>> channel = grpc.secure_channel(target, composite_credentials)
E1221 08:57:47.373061113 18747 ev_epollex_linux.cc:1482] Skipping epollex becuase GRPC_LINUX_EPOLL is not defined.
E1221 08:57:47.373136726 18747 ev_epoll1_linux.cc:1261] Skipping epoll1 becuase GRPC_LINUX_EPOLL is not defined.
E1221 08:57:47.373148066 18747 ev_epollsig_linux.cc:1761] Skipping epollsig becuase GRPC_LINUX_EPOLL is not defined.